So there are two ways to do so. But the first way is much safer.
1. Copy the project and paste it to desired location. Then open this project as open an intel xdk project.This is much safer option and you will have a copy of the old one residing in the old location.
2.Or close the XDK. Copy the project to a new location. Then open up the global settings.xdk file and change the root directory path. And now when you open the XDK you will see the new location has been updated .